This invention relates to a channel section for a scraper-chain conveyor.
Known scraper-chain converyors, which are used primarily in underground mine workings, are constituted by a series of channel sections (or pans), which are connected together in an end-to-end relationship. The channel sections are joined together in such a manner as to resist tensile forces which tend to draw the ends of the channel sections apart; whilst permitting some angular mobility, in all directions, between the channel section ends.
The channel sections of one known type of scraper-chain conveyor have sigma-section side walls and a floor plate welded to the central portions of the side walls. Each of the side walls has inwardly-extending flanges at the top, the centre, and the base, the central flange being connected to the top and base flanges by means of a V-shaped wall sections and by respective short vertical wall sections. The V-shaped wall sections define V-shaped grooves in the external surfaces of the side walls. The floor plate is welded to the central flanges of the sigma-shaped side walls. A scraper assembly circulates along the row of channel sections in upper and lower runs formed respectively above and below the floor plates. The ends of the scrapers are guided by the adjacent portions of the side walls of the channel sections.
A scraper-chain conveyor usually has a centre chain scraper assembly or an outboard chain scraper assembly. In a centre chain scraper assembly, the scrapers are attached to one (or, more usually, two) endless scraper chain which run along the centre of the conveyor; whereas, in a double outboard chain scraper assembly, the ends of the scrapers are connected to two outboard scraper chains, which run in profiled guides associated with the side walls of the conveyor sections.
The side walls of the conveyor channel sections are usually constituted by one-piece rolled sections of generally sigma-shaped profile. Side walls of different shapes and dimensions have to be provided for use with centre chain scraper assemblies and outboard chain scraper assemblies. Moreover, side walls of different dimensions and strengths have to be used to cater for different conveyor capacities, and for different operating conditions. Thus, for the various types of scraper-chain conveyor, a large number of side walls of different shape and/or size (and consisting of costly rolled sections) are required.
It is also known to make the side walls of conveyor channel sections of multi-part construction. For example, one known type of side wall has a lower profiled bar, acting as a lower run chain guide, and an upper profiled bar serving to guide the scrapers in the upper run. Such channel sections are made of sheet-metal sections, which are not capable of resisting the heavy loads that occur when conveyors are used in underground mining operations (see DE-AS 10 73 386, DE-PS 970, 381, DE-PS 848 177, DE-PS 902 236, DE-AS 11 09 087 and DE-PS 940 636).
In this connection it is also known to make channel section side walls of three bolted-together sectional members. In this case, the upper and lower members form the upper and lower flanges of the side walls, while the intermediate members carry the floor plates of the conveyor. (See DE-OS 29 06 097 and DE-OS 10 51 727). Finally, it is also known to divide the conventional sigman-shaped side walls, and to weld the lower profiled bars, which serve to guide the scrapers in the lower run, to a slide carrying the conveyor. In this case, the upper profiled bars, together with the base of the conveyor, form a conveyor trough which is suspended on the side walls of the slide by means of straps and hinge bolts (see DE-AS 22 10 897).
The aim of the invention is to provide a conveyor channel section which has great stability and uses comparatively simple, low-cost standard rolled sections; which can be produced at a lower cost than known channel sections having sigma-shaped side walls consisting of one-piece rolled sections; and which, while using standard rolled sections, can be used to adapt the side walls to suit different types of mine conveyor, so that it is possible to avoid the use of the large number of rolled sections of differing forms and/or dimensions for producing the different channel sections.